Recently, as radiology develops, computed tomography (CT) or magnetic resonance imaging (MRI) is frequently used for surgery or pre-treatment checkup. Since an internal status of a patient can be checked by reading a photograph and a 3D modeling thereof is also possible, such a medical technology is recognized as a very efficient test method.
CT imaging (or CT scan) has an advantage in that an accurate cross-sectional image is obtained and has a disadvantage in that a large amount of radiation needs to be irradiated so that a patient is inevitably exposed to the radiation. Nevertheless, CT imaging is used because it is highly accurate and it is easy to calculate a radiation dose (hereinafter, referred to as a “dose”) through a black and white photograph. In contrast, since a contrast of a tissue in the CT image is low, it is difficult to distinguish between a normal tissue and a tumor.
In the meantime, the MRI imaging uses a high frequency wave instead of radiation, so that it is stable because there is no risk of exposure to the radiation. Further, the MRI imaging may be performed to freely select a necessary angle in the body and have an excellent resolution. Therefore, in order to reduce an exposure amount to the patient, the radiology is gradually shifted from the CT imaging to the MRI imaging. However, the MIR image has an advantage in that a tumor is easily distinguished but has a disadvantage in that the MIR imaging does not use radiation so that it is difficult to calculate a dose.
Various methods have been proposed to take the advantage and overcome the disadvantage in consideration of the advantages and disadvantages of the CT imaging and MIR imaging.
One of these methodologies is to generate a composite CT image. For example, FIG. 1 is a CT image of the related art obtained by imaging a plurality of patients, FIG. 2 is a composite CT image generated by superimposing the plurality of CT images illustrated in FIG. 1, FIG. 3 is an MRI image of the related art, FIG. 4 is an image obtained by superimposing an MR simulation image of the related art and a composite CT image and then manually representing a boundary of a region of interest, and FIG. 5 is an image representing a state in which a linear attenuation coefficient is designated to the region of interest bordered in FIG. 4.
As illustrated in FIGS. 1 to 5, the composite CT image as illustrated in FIG. 2 is generated from the plurality of CT images as illustrated in FIG. 1 and is superimposed with the MR simulation image as illustrated in FIG. 3. Thereafter, a boundary of a region of interest is manually represented (see FIG. 4). Next, a linear attenuation coefficient (LAC) is designated to the region of interest bordered as illustrated in FIG. 5. A distribution diagram of a radiation dose may be obtained using one to one matching of contrast enhancement (Hounsfield unit: HU) based on the image as illustrated in FIG. 5.
However, the related art method has the following disadvantages. That is, the composite CT image uses an average value but eventually, the CT imaging needs to be performed one time. Further, when the plurality of images is superimposed, a geographical position error is incurred. Furthermore, since the average value is used, it is not CT data of an actual patient. Further, the boundary of the region of interest is manually drawn while visibly checking the boundary so that it is inconvenience and inaccurate.